What is a rigid bar that is free to move around a fixed point called?

A rigid bar that is free to move around a fixed point is referred to as a lever. This is because a lever is specifically designed to amplify force or change the direction of movement through a fulcrum or pivot point. In mechanical terms, a lever consists of a rigid bar that rotates around this fixed point, allowing the application of a force at one end to lift or move an object at the other end.

The concept of the lever is foundational in mechanics and physics, as it demonstrates how simple machines can make work easier by using a mechanical advantage. The distance from the applied force to the fulcrum in comparison to the distance from the resistance or load to the fulcrum determines how much the force is amplified.

In contrast, a beam typically refers to a structural component that supports loads and may not necessarily provide rotational movement. While a pivot generally describes the fixed point itself around which the lever rotates, it does not characterize the rigid bar. A rod is a simple term for a straight, cylindrical object and does not imply the mechanical function or properties associated with a lever. Thus, the correct identification of a rigid bar that rotates around a fixed point is indeed a lever.